As a network size becomes increasingly large, a media access control (MAC) table, a routing table, or another entry in a network device become key factors that restrain a network size. This problem is especially obvious in an ultra-large-scale data center network.
Most data center networks use a three-layer architecture, including a core layer, an aggregation layer, and an access layer. A server may access a data center network using a port of a switch located at an access layer. The switch in the data center network may forward a packet from the server using a MAC table or a routing table, that is, search the MAC table or the routing table according to information carried in the packet to obtain, from the MAC table or the routing table, a port that matches the information carried in the packet. The switch in the data center network sends the packet using the obtained port. A size of the MAC table or the routing table of the switch in the data center network depends on a chip configured in the switch in the data center network. As a result, a capacity of the data center network is limited to a specific extent.